1. Field of the Invention
The embodiments discussed herein are related to a semiconductor device and a method of manufacturing a semiconductor device.
2. Description of the Related Art
FIG. 9 is a package assembly structure view of a conventional semiconductor device. In FIG. 9, a package of a semiconductor device has a heat dissipation metal base 1 made of a copper material, an insulating circuit substrate 2 having a circuit pattern formed on an insulating substrate surface, and a semiconductor chip 3 (e.g., insulated gate bipolar transistor (IGBT)) mounted on the insulating circuit substrate 2. The insulating circuit substrate 2 is an insulating substrate such as a ceramic substrate including conductive plates on a front surface and a back surface. The package of the semiconductor device also has solder bonding layers 4 bonding between the metal base 1 and the conductive plate on the back surface of the insulating circuit substrate 2 as well as between the conductive plate on the front surface of the insulating circuit substrate 2 and the semiconductor chip 3, a resin case 5, and an external terminal 6 (main terminal, control terminal) mounted in a terminal attachment hole 5a in a peripheral wall portion of the resin case 5. The package of the semiconductor device also has a bonding wire 7 (aluminum wire) connecting an L-shaped leg portion 6a of the external terminal 6, protruding from the external terminal 6 to the inside of the resin case 5 and the conductive plate of the insulating circuit substrate 2, and a terminal pressing frame 10. The L-shaped leg portion 6a is a portion of the L-shaped external terminal 6 disposed within the resin case 5 to protrude inside the resin case 5.
The package assembly structure of FIG. 9 has the terminal pressing frame 10 so as to electrically insulate and separate the L-shaped leg portion 6a of the external terminal 6 protruding inside the resin case 5 and the metal base 1 overlapped with the case bottom surface side from each other and to press and prevent the L-shaped leg portion 6a from moving from a fixed position. The frame-shaped terminal pressing frame 10 is made of an insulating material and fitted inside of the resin case 5 so that the terminal pressing frame 10 is interposed between a lower surface of the L-shaped leg portion 6a and the metal base 1.
The terminal pressing frame 10 is made of a resin material equivalent to the resin case 5 and, after the external terminal 6 is mounted to the resin case 5, the terminal pressing frame 10 is fitted to an inner periphery of the resin case 5, and the heat dissipation metal base 1 overlapped on the lower surface side of the resin case 5 and the terminal pressing frame 10 are fixed to each other by an adhesive (e.g., a silicone adhesive).
In the wiring structure of FIG. 9, an upper surface main electrode of the semiconductor chip 3 is connected via the circuit pattern of the insulating circuit substrate 2 through the bonding wire 7 wired to the external terminal 6; however, in another structure, the upper surface main electrode of the semiconductor chip 3 and the external terminal 6 may be connected directly through a wire.
FIG. 10 is a plane view of a package of a conventional semiconductor device. Arrangement positions of the external terminals 6 differ depending on the product model, specifications specified by a user, etc. Therefore, in an existing technique, terminal attachment holes 5a formed in a peripheral wall portion of the resin case 5 are assigned and formed in advance so as to cope with all the specifications (see, for example, Japanese Laid-Open Patent Publication Nos. 2008-235651 and 2008-252055). As a result, the resin case 5 can be utilized as a common component, which eliminates the need for preparing the resin case 5 for each product model or specification specified by a user.
When the external terminals 6 are mounted to the resin case 5 at arrangement positions specified for each model of the semiconductor device, the terminal attachment holes 5a corresponding to the model or specified specification are selected from a multiplicity of the terminal attachment holes 5a assigned and formed in advance in the peripheral wall portion of the resin case 5. The external terminals 6 are then mounted in the selected terminal attachment holes 5a. 
FIG. 11 is an explanatory view of a package assembly procedure of a conventional semiconductor device. First, out of the terminal attachment holes 5a formed in a peripheral wall portion of the resin case 5, the external terminal 6 is inserted and mounted in the selected terminal attachment hole 5a from the bottom surface side of the resin case 5 as indicated by arrow (1).
Subsequently, as indicated by arrow (2), an adhesive is applied to the whole periphery of the peripheral wall portion of the resin case 5 and the L-shaped leg portion 6a of the external terminal 6. To ensure a wire bonding property, the adhesive is applied one by one to the L-shaped leg portions 6a of the external terminals 6 mounted in the terminal attachment holes 5a. Since the adhesive is applied to the entire periphery of the peripheral wall portion of the resin case 5, the adhesive ends up at the terminal attachment holes 5a of the resin case 5 without the inserted external terminals 6.
Subsequently, the terminal pressing frame 10 is fitted from the bottom surface side of the resin case 5 as indicated by an arrow (3) to press the external terminal 6 from the lower side.
Subsequently, an adhesive is applied to a bottom surface of the terminal pressing frame 10, the surface contacting the metal base 1. A substrate assembly assembled at a different step and made up of the metal base 1, the insulating circuit substrate 2, and the semiconductor chip 3 is attached to the bottom surface side of the resin case 5 as indicated by an arrow (5) and the adhesive is thermally cured. As a result, the adhesive fixes the L-shaped leg portion 6a of the external terminal 6 and the terminal pressing frame 10 to each other as well as a peripheral edge of the metal base 1 and the terminal pressing frame 10 to each other.
Subsequently, the bonding wire (aluminum wire) 7 is bonded between the L-shaped leg portion 6a of the external terminal 6 and a conductive pattern of the insulating circuit substrate 2 by an ultrasonic bonding method, and the inside of the resin case 5 is filled with a sealing resin (not depicted) and then covered by a case lid (not depicted) to complete a product.